ARM: tegra: Move AHB Kconfig to drivers/amba

This will allow the Kconfig option to be shared among 32-bit and 64-bit
ARM.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 1a693d3..af02a8a 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -1,5 +1,7 @@
 menu "Device Drivers"
 
+source "drivers/amba/Kconfig"
+
 source "drivers/base/Kconfig"
 
 source "drivers/bus/Kconfig"